TNFα G308A polymorphism is associated with resilience to sleep deprivation-induced psychomotor vigilance performance impairment in healthy young adults.

Cytokines such as TNFα play an integral role in sleep/wake regulation and have recently been hypothesized to be involved in cognitive impairment due to sleep deprivation. We examined the effect of a guanine to adenine substitution at position 308 in the TNFα gene (TNFα G308A) on psychomotor vigilance performance impairment during total sleep deprivation. A total of 88 healthy women and men (ages 22-40) participated in one of five laboratory total sleep deprivation experiments. Performance on a psychomotor vigilance test (PVT) was measured every 2-3h. The TNFα 308A allele, which is less common than the 308G allele, was associated with greater resilience to psychomotor vigilance performance impairment during total sleep deprivation (regardless of time of day), and also provided a small performance benefit at baseline. The effect of genotype on resilience persisted when controlling for between-subjects differences in age, gender, race/ethnicity, and baseline sleep duration. The TNFα G308A polymorphism predicted less than 10% of the overall between-subjects variance in performance impairment during sleep deprivation. Nonetheless, the differential effect of the polymorphism at the peak of performance impairment was more than 50% of median performance impairment at that time, which is sizeable compared to the effects of other genotypes reported in the literature. Our findings provided evidence for a role of TNFα in the effects of sleep deprivation on psychomotor vigilance performance. Furthermore, the TNFα G308A polymorphism may have predictive potential in a biomarker panel for the assessment of resilience to psychomotor vigilance performance impairment due to sleep deprivation.

Maternal protein deprivation: changes in systemic renin-angiotensin system of the mouse fetus.

We tested the hypothesis that maternal protein deprivation during gestation results in changes in expression of the systemic renin-angiotensin system in fetal mice. Fetal weight was decreased significantly as a consequence of 50% maternal protein deprivation during second half of gestation. In fetal liver, angiotensinogen protein expression was reduced significantly despite a significant increase in messenger RNA (mRNA). In fetal kidneys, both mRNA and protein levels of renin were increased significantly. In the lungs, we observed a decrease in both angiotensin-converting enzyme I and II mRNA expression, whereas protein expression of both isoforms was increased significantly. The fetal heart showed significant increases in expression of angiotensin II type 1 (AT-1) and type 2 (AT-2) receptors mRNA. Protein expression of AT-1 receptors increased, while that of AT-2 receptors decreased. We conclude that maternal low-protein diet during gestation leads to significant changes in expression of the systemic renin-angiotensin system in fetal mice and may be important in the genesis of hypertension in the adult.